Super Mario Maker is fun, really fun in fact, which has got plenty of people wondering if a 'Zelda Maker' would also be worthwhile.
If Zelda Maker did exist, maybe it would look a little bit like this project.
YouTube user Dream Mix uploaded this video, of a work in progress 'Zelda Maker'. Its just a series of experiments and if/when Nintendo decide to issue the old cease and desist request, Dream Mix is happy to change up the assets.
As interesting as this is, I'm not sure a Zelda Maker would have the same impact as Mario Maker. It's relatively easy to create a simple Mario level, but creating a complete Zelda world? It seems like a far grander task, definitely not as accessible as it needs to be for a product like 'Zelda Maker' to be worthwhile for a company like Nintendo. This might work better as something like RPG Maker -- a first step for people who actually want to make their own video games.
Still, this is pretty cool.